Prenatal Exposure to Pyrethroid Insecticides and Infant Neurocognitive Development at 3 Years of Age

Abstract

ISEE-0874 Background and Objective: We previously documented widespread use of spray insecticides among pregnant African American and Dominican women living in low-income, urban neighborhoods in New York City. Recently, we demonstrated a change in pesticide exposures as pyrethroids replace organophosphates following the 2000–2001 U.S. EPA pesticide regulations. Pyrethroids are purportedly safer insecticides due to low volatility and rapid metabolism, yet experimental data suggest the potential for neurotoxicity following prenatal exposure. The objective of this study is to explore the association between prenatal exposure to permethrin, a common pyrethroid, and piperonyl butoxide (PBO), a pyrethroid synergist, and neurodevelopment among mother-infant pairs in our prospective cohort. Methods: Neurodevelopment was assessed using the Bailey Scales of Infant Development (BSID-II) at 36-months of age. Exposure variables included permethrin and PBO in 3rd trimester personal air samples and permethrin in maternal and cord plasma collected at birth. We employed multiple logistic regression models treating PBO as a categorical variable (reference group = nondetectable, 1st-4th groups = quartiles of detectable levels) and permethrin as a dichotomous variable (nondetect vs. detect). All models adjusted for gender, ethnicity, prenatal ETS exposure, gestational age, maternal education, maternal IQ and quality of home environment. Results: The odds of delayed mental development were 4.47 times as great (95% CI: 1.75–11.16; P = 0.002) among children in the highest quartile of PBO exposure (median = 4.34 ng/m3) compared to children with lower prenatal piperonyl butoxide exposures (≤ 0.85 ng/m3). There were no significant associations between cis- or trans-permethrin in either personal air or plasma and BSID-II scores at 36 months among children in this cohort. Conclusion: Exploratory results show a significant association between PBO in personal air collected during pregnancy and delayed neurodevelopment at 36-months among children in this cohort.